Germanium compounds chemical properties

The chemical properties of germanium fall between those of silicon and tin. It forms both the divalent and tetravalent compounds, the oxidation state +4 being more stable than the +2 oxidation state. The metal is stable in air and water at ambient temperatures. However, it reacts with oxygen at elevated temperatures forming divalent and tetravalent oxides, GeO and Ge02. 

Elemental silicon is relatively stable in most substances at ordinary temperatures. Silicon shows similarity with other elements of its group, especially with germanium in many chemical properties. It forms tetravalent compounds with tetrahedral geometry almost exclusively. However, only in silicon monoxide, SiO, is its valence +2. Also, unlike carbon, silicon does not form unsaturated double or triple bond compounds. Silicon dissolves in germanium... 

Laboratory research on organic compounds of the silicon subgroup elements showed that they ought to be divided into two subgroups (dyads) in accordance with their similarity in chemical properties and biological activity. Silicon and germanium derivatives were placed in the first one while the tin and lead derivatives belong to the second. 

If the trace element and the collector have opposite chemical properties (acidic, basic), the co-precipitation may be the result of formation of chemical compounds. For example, traces of germanium or vanadium form germanates or vanadates in co-precipitation with Fe(III)-, A1-, or La- hydroxides, while traces of tungsten or molybdenum, on co-precipitation with Fe(III) hydroxide, form the corresponding Fe(III) tungstate or molybdate. 

Chemical and stereochemical properties of compounds with silicon- or germanium-transition metal bonds. E. Colomer and R. J. P. Corriu, Top. Curr. Chem., 1981, 96, 79-107 (68). 

Colomer, E., and Corriu, R. J. P. Chemical and Stereochemical Properties of Compounds with Silicon or Germanium-Transition Metal Bonds, 96, 79-110 (1981). 

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